Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id wBBMdrWe016382 for ; Tue, 11 Dec 2018 23:40:00 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gWqc0-0004zE-3F for rs_out_1@blacksheep.org; Tue, 11 Dec 2018 22:34:44 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gWqaU-0004yv-Aa for rsgb_lf_group@blacksheep.org; Tue, 11 Dec 2018 22:33:10 +0000 Received: from proofpoint-cluster.metrocast.net ([65.175.128.136]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1gWqaN-0001cW-O3 for rsgb_lf_group@blacksheep.org; Tue, 11 Dec 2018 22:33:04 +0000 Received: from Rob64PC (d-69-161-84-15.cpe.metrocast.net [69.161.84.15]) by apple.metrocast.net (8.14.7/8.14.4) with SMTP id wBBMX0Mj012699 for ; Tue, 11 Dec 2018 22:33:00 GMT Message-ID: <7CF7D632B96D471BA659A32CF876943B@Rob64PC> From: "Rob Renoud" To: References: <941104406.2050754.1544486244944.ref@mail.yahoo.com> <941104406.2050754.1544486244944@mail.yahoo.com> In-Reply-To: <941104406.2050754.1544486244944@mail.yahoo.com> Date: Tue, 11 Dec 2018 22:33:00 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 16.4.3528.331 X-MimeOLE: Produced By Microsoft MimeOLE V16.4.3528.331 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.22.26,1.0.8,0.0.0000 definitions=2018-12-11_08:2018-12-11,2018-12-11,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=1 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1810110000 definitions=main-1812110198 X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Markus, Thanks for the tip about using a double balanced mixer (DBM) for generating the 180 degree phase shift. It works perfectly and simplified my hardware arrangement with the HP3325A! I did insert a 330 o [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [65.175.128.136 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 08757f49bceb24af7a81ea2a82227211 Subject: LF: Re: LF and VLF EbNaut Content-Type: multipart/alternative; boundary="----=_NextPart_000_00AA_01D491A1.78E0D630" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_MESSAGE, MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false This is a multi-part message in MIME format. ------=_NextPart_000_00AA_01D491A1.78E0D630 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Markus, Thanks for the tip about using a double balanced mixer (DBM) for = generating the 180 degree phase shift. It works perfectly and = simplified my hardware arrangement with the HP3325A! I did insert a 330 = ohm resistor in series with the RS-232 RTS line to limit current through = the DBM. FYI, I do use a 10 MHz GPS-based input to my HP-3325A so = frequency accuracy and stability concerns are minimum. Tips always welcome & 73, Rob - K3RWR From: Markus Vester=20 Sent: Monday, December 10, 2018 11:57 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: LF and VLF EbNaut Yes for LF I would also recommend the method with signal generator, = relay and ebnaut-tx software, it's really not difficult to get started. = Instead of the relay, a double balanced diode mixer also works well, = with the DC-coupled IF port driven directly from RS232. If you happen to = have a linear PA you could optionally insert a simple C-R lowpass for = shaped keying. The realtime clock of the sending PC should be steered by = NTP, or alternatively using NMEA from an external GPS.=20 I think that frequency accuracy needs to be much better than 5e-8. To = keep the phase drift within 30=C2=B0 over half an hour, the frequency = should ideally be known to better than 46 uHz, or about 3e-10 (0.3 ppb). = Most simple OCXOs cannot hold up to that. When the signal is strong, one = can sometimes still obtain a decode by aligning the slope of the symbol = phase graph. But this won't work for weak signals, and poking around = blindly for a frequency offset that may or may not produce a decode can = be a cumbersome and frustrating affair. The best choice is a GPS derived = oscillator, or a well calibrated Rubidium source.=20 When will we see you? Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung----- Von: Rob Renoud An: rsgb_lf_group Verschickt: Mo, 10. Dez 2018 23:33 Betreff: Re: LF: LF and VLF EbNaut Paul, Chris and EbNaut LF, Stefan makes a good argument for trying what you have for TX. The = HP-3325A specs show a frequency accuracy of +- 5 EE-8 and stability = (option 001) of +- 5 EE-6. The HP-3325A should work ok on 2200m with a = message duration of 28 minutes or less. The 180 phase reversal is easily implemented using a DPDT relay with a = 1:1 transformer connected between the 3325 generator and the amp input. = Drive the relay with the RS-232 RTS or CTS signal from the computer = running ebnaut-tx.exe found on http://abelian.org/ebnaut/ such that the = relay shifts the phasing of the input to the transformer. Time and frequency are important on the decoding end. Try to get them = as accurate as possible on the TX end. For 2200m a good starting message format is: Code: 8K19A Symbol Period: 3 CRC: 16 Characters: 5 Duration: 25:36.00 Repeat on the hour and half-hour Announce your beacon and give it a try. Lot=E2=80=99s of LF EbNaut = listeners to let you know if it=E2=80=99s working out... Comments and other suggestions are welcome. 73, Rob - K3RWR On Dec 10, 2018, at 15:58, = wrote: BPSK transitions cause key clicks with non linear transmitters / = amplifiers. As a practical matter ... with the high Q transmitting = antennas in use ... and that it's unlikely you'll have next door = neighbor interested in LF reception ... it hasn't been a much of a = problem. Jay W1VD ----- Original Message ----- From: "DK7FC" To: Sent: Monday, December 10, 2018 11:08 AM Subject: Re: LF: LF and VLF EbNaut Hi Paul, Am 09.12.2018 20:02, schrieb N1BUG: The first thing people want to know is what equipment is required for LF EbNaut and how much = is this going to cost? But answers are hard to come by. I could never get an answer as to whether my HP 3325B with high stability option was good enough. The problem is also on the other side. I don't know what a HP3325B = is, or, at least, i don't know the technical details since i don't own = one. So i can give no advice how to use it for EbNaut transmitting Also there are different methods and each radio amateur is convinced = about his own design. Some methods may be easier to realise but less precise and less = flexible. So based on the skills and needs and parts available one will = decide for a certain design. Thus it is not so easy to write up 'the' way to go, there are many = ways. For example, there could be a 'how to EbNaut' including Linux = components like ebkey, which will be useless for someone who insists to = avoid using Linux... So if you're asking the group, then you will get different advice, = from different designs. And this will be confusing! So concentrate on = the basics and then choose your own design. I suggest to start in steps, don't plan to build the perfect system = until the season is over. Basically all you need is an absolutely stable signal generator and = a tool for inverting the phase and managing the timing. This can be done = with Windows and Linux. I think you are one of those who avoid using Linux. So then, you = need SpecLab to generate the PSK. But step 1 is the stable signal. One method is to use an up-converter and SpecLab to generate EbNaut. = SpecLab can generate a tone on e.g. 12500 Hz which is then mixed with = 125 kHz, so there is an output at 137.5 kHz. This is how i do it here. I can tell you about other methods but this may lead to confusion = already. Maybe there is one step before step 1, call it step 0: You need to = decide, "YES i will now start to transmit EbNaut and i will buy to = necessary components, learn what is necessary to understand, knowing it = means effort!" What kind of signal generator do you use now? When I asked about amplifiers for EbNaut I was told linear is a must Do you remember who said that? but now I find people are doing it with nonlinear amplifiers Yes, a linear amplifier is not needed. It is BPSK, the output power = is always at 100%, which is good :-) 73, Stefan ------=_NextPart_000_00AA_01D491A1.78E0D630 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Markus,
 
Thanks for the tip about using a double balanced mixer (DBM) for = generating=20 the 180 degree phase shift.  It works perfectly and simplified my = hardware=20 arrangement with the HP3325A!  I did insert a 330 ohm resistor in = series=20 with the RS-232 RTS line to limit current through the DBM.  FYI, I = do use a=20 10 MHz GPS-based input to my HP-3325A so frequency accuracy and = stability=20 concerns are minimum.
 
Tips always welcome & 73,
Rob - K3RWR
 
Sent: Monday, December 10, 2018 11:57 PM
To: rsgb_lf_group@blacksheep.org =
Subject: Re: LF: LF and VLF EbNaut
 
Yes for LF I would also recommend the method with signal = generator,=20 relay and ebnaut-tx software, it's really not difficult to get started. = Instead=20 of the relay, a double balanced diode mixer also works well, with the = DC-coupled=20 IF port driven directly from RS232. If you happen to have a linear PA = you could=20 optionally insert a simple C-R lowpass for shaped keying. The realtime = clock of=20 the sending PC should be steered by NTP, or alternatively using NMEA = from an=20 external GPS.

I think that=20 frequency accuracy needs to be much better than 5e-8. To keep the phase = drift=20 within 30=C2=B0 over half an hour, the frequency should ideally be known = to better=20 than 46 uHz, or about 3e-10 (0.3 ppb). Most simple OCXOs cannot hold up = to that.=20 When the signal is strong, one can sometimes still obtain a decode by = aligning=20 the slope of the symbol phase graph. But this won't work for weak = signals, and=20 poking around blindly for a frequency offset that may or may not produce = a=20 decode can be a cumbersome and frustrating affair. The best choice is a = GPS=20 derived oscillator, or a well calibrated Rubidium source.

When will we see you?

Best 73,
Markus=20 (DF6NM)

-----Urspr=C3=BCngliche=20 Mitteilung-----
Von: Rob Renoud=20 <k3rwr@md.metrocast.net>
An: = rsgb_lf_group=20 <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 10.=20 Dez 2018 23:33
Betreff: Re: LF: LF and VLF = EbNaut
Paul, Chris and EbNaut LF,
 
Stefan makes a good argument for trying what = you have for=20 TX.   The HP-3325A specs show a frequency accuracy of +- 5 = EE-8 and=20 stability (option 001) of +- 5 EE-6.  The HP-3325A should work ok = on 2200m=20 with a message duration of 28 minutes or less.
 
The 180 phase reversal is easily implemented = using a DPDT=20 relay with a 1:1 transformer connected between the 3325 generator and = the amp=20 input.  Drive the relay with the RS-232 RTS or CTS signal from the = computer=20 running ebnaut-tx.exe found on http://abelian.org/ebnaut/ such that=20 the relay shifts the phasing of the input to the transformer.
 
Time and frequency are important on the = decoding=20 end.  Try to get them as accurate as possible on the TX end.
 
For 2200m a good starting message format = is:
 
Code:  8K19A
Symbol Period:  3
CRC: 16
Characters: 5
Duration:  25:36.00
Repeat on the hour and half-hour
 
Announce your beacon and give it a try.  = Lot=E2=80=99s of LF=20 EbNaut listeners to let you know if it=E2=80=99s working out...
 
Comments and other suggestions are = welcome.
 
73,
Rob - K3RWR
 
 
 
 
 
 
On Dec 10, 2018, at 15:58, <jrusgrove@comcast.net> = <jrusgrove@comcast.net> = wrote:
BPSK transitions cause = key clicks with=20 non linear transmitters / amplifiers. As a practical matter ... with = the high=20 Q transmitting antennas in use ... and that it's unlikely you'll have = next=20 door neighbor interested in LF reception ... it hasn't been a much of = a=20 problem.

Jay W1VD



----- Original=20 Message ----- From: "DK7FC" <selberdenken@posteo.de><= /SPAN>To: <rsgb_lf_group@blacksheep.= org>Sent: Monday, December 10, = 2018 11:08=20 AM
Subject: Re: = LF: LF and VLF=20 EbNaut


Hi = Paul,

Am 09.12.2018 = 20:02,=20 schrieb N1BUG:
The first = thing people=20 want
to know is = what=20 equipment is required for LF EbNaut and how much is
this going = to cost? But=20 answers are hard to come by. I could never
get an = answer as to=20 whether my HP 3325B with high stability option
was good=20 enough.
The problem is = also on the=20 other side. I don't know what a HP3325B is, or, at least, i don't = know the=20 technical details since i don't own one. So i can give no advice how = to use=20 it for EbNaut transmitting
Also there are = different=20 methods and each radio amateur is convinced about his own = design.
Some methods = may be easier=20 to realise but less precise and less flexible. So based on the = skills and=20 needs and parts available one will decide for a certain = design.
Thus it is not = so easy to=20 write up 'the' way to go, there are many ways. For example, there = could be a=20 'how to EbNaut' including Linux components like ebkey, which will be = useless=20 for someone who insists to avoid using Linux...
So if you're = asking the=20 group, then you will get different advice, from different designs. = And this=20 will be confusing! So concentrate on the basics and then choose your = own=20 design.
I suggest to = start in=20 steps, don't plan to build the perfect system until the season is=20 over.

Basically all = you need is=20 an absolutely stable signal generator and a tool for inverting the = phase and=20 managing the timing. This can be done with Windows and = Linux.
I think you = are one of=20 those who avoid using Linux. So then, you need SpecLab to generate = the=20 PSK.
But step 1 is = the stable=20 signal.
One method is = to use an=20 up-converter and SpecLab to generate EbNaut. SpecLab can generate a = tone on=20 e.g. 12500 Hz which is then mixed with 125 kHz, so there is an = output at=20 137.5 kHz. This is how i do it here.
I can tell you = about other=20 methods but this may lead to confusion already.
Maybe there is = one step=20 before step 1, call it step 0: You need to decide, "YES i will now = start to=20 transmit EbNaut and i will buy to necessary components, learn what = is=20 necessary to understand, knowing it means effort!"

What kind of = signal=20 generator do you use now?

When I asked = about=20 amplifiers for EbNaut I was told
linear is a=20 must
Do you = remember who said=20 that?
but now I = find people=20 are doing it with nonlinear
amplifiers
Yes, a linear = amplifier is=20 not needed. It is BPSK, the output power is always at 100%, which is = good=20 :-)

73, = Stefan


= ------=_NextPart_000_00AA_01D491A1.78E0D630--